Not sure why prices are down for found my 1st 6 groove barrel Smith Corona at a gun show bore was so dark you couldn't see any rifling got it home and shot all the crap out and it had 6 grooves.
A few years ago I glommed a sporterized Smith Corona 03A3 with a 6 groove barrel. The rifle is in a sporter stock with a Redfield target sight and an intact 12-42 barrel.